My experience with Rockwells has been this:
If like mentioned above you really want to go with very large tires, then they may be a way to go.
If not, then you are looking at a lot more weight you will be adding. They are also big to work on. The drums are very heavy and the brake shoes generally run $50 per wheel. The wheel cylinders are MV supplier only, as nothing else seems to cross over. You will have to go springover, to clear any oil pan because of the giant center section sticking straight up. Wheels will either be for a deuce, or custom built.
As for CUCV stuff, its all GM. All available off the shelf, easier (in my opinion) to work with, lighter overall, which to me means less to drag out of a stuck on the trail, and your wheel options are endless. Plus you get 4 wheel discs to boot.
"Free advice is worth what you pay for it."™